B. BAERTSCHI, The moral impact of the status of natural beings, RThPh 2003/IV, p. 329-344.
Since Hume, the point has been stressed that an “ought” cannot logically be deduced from an “is”. Yet each time we ask ourselves how we should behave towards a natural being, such as an animal or an embryo, we refer to what some authors cali its “moral status”. However, that which is qualified as “moral” belongs in fact to the realm of what “is”. Consequently, it is impossible to avoid ontology if we want to determine how we ought to treat natural beings, even if there are many other considerations, particularly when we ask about the value of the life of human beings whose existence is much diminished.